1. Field of the Invention
The present invention relates to an image forming apparatus which forms an image on a medium by utilizing a photoreceptor.
2. Description of the Related Art
For example, a color laser printer forms an image on a medium (e.g. a printing paper) by utilizing a plurality of photoreceptors. Each of the photoreceptors is capable of retaining an electrostatic latent image. When developer is supplied to each of the photoreceptors, the developer is stuck to an area on which the electrostatic latent image of each photoreceptor is formed, and whereby the electrostatic latent image of each photoreceptor is visualized. Many color laser printers have a belt facing each of the photoreceptors. One embodiment of such belts is referred to as “conveyance belt.” The conveyance belt conveys the medium through an area which faces each photoreceptor. Developer retained by each photoreceptor is transferred onto the medium which is being conveyed by the conveyance belt. Thus, an image is formed on the medium. Another embodiment of the belts is referred to as “intermediate transfer belt.” Developer retained by each photoreceptor is transferred onto the intermediate transfer belt. The developer transferred onto the intermediate transfer belt is further transferred onto the medium. Thus, an image is formed on the medium.
Japanese Patent Application Publication No. 2004-279994 discloses a laser printer which has a conveyance belt. This laser printer has a charge removal needle which is located between two photoreceptors being adjacent in a direction of transferring a medium. The conveyance belt is electrostaticly charged by the photoreceptors located on the upstream side. The charge removal needle removes electric charges from the conveyance belt by the time the conveyance belt reaches the photoreceptors located on the downstream side.